1. Field of the Invention
The invention relates to an ergonomic lightweight hand pressure sensor-warning device, for use with handheld objects like sport devices, steering devices, writing devices or computer devices, as well as the method for its assembly.
The invention also relates to an assembly method of a hand pressure sensor warning device. The invention also relates to a membrane switch for use in a hand pressure sensor warning device.
2. Background Art
The warning device is used to correct handgrip forces applied to handgrips of handheld objects or equipment, in particular for use with sports devices including but not limited to tennis, squash, badminton, table tennis, baseball, cricket, hockey, fencing, billiards, pool, shooting sports, rowing, skiing, etc. and also for use by drivers of vehicles, boats and ships, for use by machine operators, medical personnel and other applications to correct grip pressure exerted on the handheld object or equipment and to improve performance or to prevent muscle stress or the risk of injury. The invention can also be used to correct hand- and finger forces on handheld writing tools, such as pens and pencils during writing or on hand operated computer interface devices such as a computer mouse. The ergonomic lightweight hand pressure sensor warning device also serves to correct hand pressure forces on the steering wheel of a vehicle or helm of a vessel or the control handle of aircraft, helicopters, and other industrial machines.
To perform a correct hit or hand movement, for example, with tennis, squash, badminton, table tennis, baseball, softball, cricket, hockey, fencing, billiard, shooting sports, rowing, in which different equipment is held in one or both hands, is difficult to learn, especially when precision and grip strength is important for the level of performance. Inadequate grip strength or too much grip strength deteriorates performance and can result in injuries, caused by incorrect handgrip or handgrip forces. In certain cases, excessive handgrip forces can cause muscle or joint injuries in the fingers, hands, wrist, elbows, arms, shoulders and back.
Known devices are described in U.S. Pat. No. 5,377,541 and WO 95/311258, which in the golf world are known as the “Smartgrip”. Both devices are mainly constructed from sensor elements with accompanying electronics, power supply and sound device, all attached to the handgrip of a golf club by means of a spirally wrapped band with “C” clips (or internally attached) according to U.S. Pat. No. 5,377,541 or by means of a cylindrical flexible hose according to WO 95/311258.
Another known device according to WO 99/27853 encloses a capacitive sensor constructed from different pressure sensitive conductive plates with isolating layers in between and integrated in a handgrip area of a racquet, bat, club or other equipment. Simple installation on a racquet, bat, club or other equipment by an end-user is not possible. Further this very sensitive hardware can not be removed for repair or maintenance without the help of an expert. The capacitive pressure sensors are very sensitive to temperature changes and moisture. This prevents a long-life guarantee. Such capacitive sensors with an adequate power supply and miscellaneous electronic components are rather expensive, which results in substantially higher production costs for a racquet, bat or other equipment using such technology.
Another disadvantage of this and of all other known warning devices is the large physical mass required. This substantially influences the appropriate moment of inertia of the golf club, racquet, bat or other equipment. Hits and movements learned with such a warning device need to be learned again without the use of these training aids, or with conventional racquets, bats and other equipment. Due to the high cost price, these types of warning device are not suitable for premium and or promotional give-away products. The known warning devices are too big, too heavy, too complicated and too expensive to be used with small handheld devices like pens or computer mouse's.